Security devices for the balance springs of watches



L. LOGE Aug. 29, 1961 SECURITY DEVICES FOR THE BALANCE SPRINGS OFWATCHES Filed Feb. 28, 1958 2,997,841 SECURITY DEVICES FOR THE BALANCESPRINGS F WATCHES Lars Loge, Spregaten 15, Stavanger, Norway Filed Feb.28, 1958, Ser. No. 718,261 Claims priority, application Norway Mar. 3,1957 2 Claims. (Cl. 58107) This invention concerns a security device forthe balance springs of watches, in particular wrist watches. It has beenfound, especially with small watches, such as wrist watches that thebalance spring which is attached at its inner end to the balance wheelshaft and at its outer end to an adjustable anchorage, has a tendency tobecome dislocated should the watch be subjected to impacts, becomingwedged or causing irregular running. The end of the outermost winding ofthe spring, which is threaded generally through a slit in a postunderneath the hairspring regulator also has the same tendency to becomedislocated and to jam when subjected to impact-although not sofrequently as is the case with the outermost part of the springpreceding the anchorage. The invention has for object to eliminate thesetroublesome jammings which are a great inconvenience to watchmakers,

According to the invention, one or more spring tongues capable ofvibrating upon shock are associated with the balance spring mounting toassist the balance spring to return to normal position afterdislocation.

A device according to the invention is shown by Way of example in theaccompanying drawing, wherein:

FIGURE 1 shows in plan a balance spring assembly according to theinvention.

FIGURE 2 is a side elevation looking in the direction of the arrows 22FIGURE 1 and FIGURE 3 is a side elevation looking in the direction ofthe arrows 3-3 FIGURE 1.

Referring to the drawings the reference 1 indicates a watch casing and 2the balance wheel support plate provided with an extension 3 fitted witha downward directed post 5, to which the outer end of the balance orhair spring 4- is fastened. The inner end of the spring 4 is fastened toa sleeve 6 on a balance wheel arbor 7. The outermost winding of thespring passes through a slit or groove 13 in the downwardly directedpost 10 forming part of a regulator 9 for the hairspring. When the watchis subjected to a violent shock, the spring 4 tends to jam against thepost and partly against the post 10. To

tea ii atent G avoid this effectively, there is provided a tongue 11 ofspring metal attached to lower end of the post 5, the tongue curvesupwardly creating a slanting passage for the spring 4 if dislocated toslide or glide back into its appropriate place.

The tongue 11, which has a free upper end and being made of springymaterial, will start vibrating when the watch is subjected to shock,thereby facilitating the guiding back of spring 4. To the same effect asimilar tongue 12 has in the example illustrated, been attached to thelower end of the post 10. The spring tongues 11 and 12 need notnecessarily be fastened to the posts 5 and 10, but may be attached toindependent posts or formed as an integral part of the post 5, 10 or thehair-spring regulator extension 3 respectively.

What I claim and desire to secure by Letters Patent is:

1. In a watch balance spring assembly including a balance wheel supportplate, an extension on said plate for supporting a post, a post fittedon said extension and extending downwardly from the balance wheelsupport plate, an arbor on said balance wheel, a sleeve on said balancewheel arbor, a balance spring fastened on its inner end to said sleeve,a regulator for said spring constituting a post having a slit throughwhich the outermost winding of said spring passes, a tongue of springmetal extending outwardly from the axis of said post in an inclined pathtoward the plane of said support plate whereby said tongue preventsentanglement of the balance spring with said post by creating a slantingpassageway for said spring when said spring is dislocated by a shock tojam against said post and thereby provides a return guide for saidbalance spring.

2. The device of claim 1 wherein the said tongue is attached to thelower end of said post and there is provided an additional tongueattached to said regulator to facilitate guiding of said spring awayfrom a jammed position against said post when the watch is subjected toimpact thereby facilitating relocation of the balance spring.

References Cited in the file of this patent UNITED STATES PATENTS361,850 Van Strait Apr. 26, 1887 2,105,966 Bowen Jan. 18, 1938 FOREIGNPATENTS 219,447 Switzerland May 16, 1942

